Quantum teleportation — the transmission and reconstruction over arbitrary distances of the state of a quantum system — is demonstrated experimentally. During teleportation, an initial photon which carries the polarization that is to be transferred and one of a pair of entangled photons are subjected to a measurement such that the second photon of the entangled pair acquires the polarization of the initial photon. This latter photon can be arbitrarily far away from the initial one. Quantum teleportation will be a critical ingredient for quantum computation networks.

/pdf/experimental-quantum-teleportation-1cqrxvlpex.pdf

Experimental quantum teleportation

http://mechanism.ucsd.edu/teaching/F12/cs200/Readings/larkin.whyadiagramissometimesworth.1987.pdf

Why a Diagram is (Sometimes) Worth Ten Thousand Words

Stochastic thermodynamics as reviewed here systematically provides a framework for extending the notions of classical thermodynamics such as work, heat and entropy production to the level of individual trajectories of well-defined non-equilibrium ensembles. It applies whenever a non-equilibrium process is still coupled to one (or several) heat bath(s) of constant temperature. Paradigmatic systems are single colloidal particles in time-dependent laser traps, polymers in external flow, enzymes and molecular motors in single molecule assays, small biochemical networks and thermoelectric devices involving single electron transport. For such systems, a first-law like energy balance can be identified along fluctuating trajectories. For a basic Markovian dynamics implemented either on the continuum level with Langevin equations or on a discrete set of states as a master equation, thermodynamic consistency imposes a local-detailed balance constraint on noise and rates, respectively. Various integral and detailed fluctuation theorems, which are derived here in a unifying approach from one master theorem, constrain the probability distributions for work, heat and entropy production depending on the nature of the system and the choice of non-equilibrium conditions. For non-equilibrium steady states, particularly strong results hold like a generalized fluctuation–dissipation theorem involving entropy production. Ramifications and applications of these concepts include optimal driving between specified states in finite time, the role of measurement-based feedback processes and the relation between dissipation and irreversibility. Efficiency and, in particular, efficiency at maximum power can be discussed systematically beyond the linear response regime for two classes of molecular machines, isothermal ones such as molecular motors, and heat engines such as thermoelectric devices, using a common framework based on a cycle decomposition of entropy production. (Some figures may appear in colour only in the online journal) This article was invited by Erwin Frey.

/pdf/stochastic-thermodynamics-fluctuation-theorems-and-molecular-2epwyvmpf0.pdf

Stochastic thermodynamics, fluctuation theorems and molecular machines

Carbon nanotubes subject to large deformations reversibly switch into different morphological patterns. Each shape change corresponds to an abrupt release of energy and a singularity in the stress-strain curve. These transformations, simulated using a realistic many-body potential, are explained by a continuum shell model. With properly chosen parameters, the model provides a remarkably accurate ``roadmap'' of nanotube behavior beyond Hooke's law.

/pdf/nanomechanics-of-carbon-tubes-instabilities-beyond-linear-c39bdv9fp7.pdf

Nanomechanics of carbon tubes: Instabilities beyond linear response.

The widespread use of controlled molecular-level motion in key natural processes suggests that great rewards could come from bridging the gap between the present generation of synthetic molecular systems, which by and large rely upon electronic and chemical effects to carry out their functions, and the machines of the macroscopic world, which utilize the synchronized movements of smaller parts to perform specific tasks. This is a scientific area of great contemporary interest and extraordinary recent growth, yet the notion of molecular-level machines dates back to a time when the ideas surrounding the statistical nature of matter and the laws of thermodynamics were first being formulated. Here we outline the exciting successes in taming molecular-level movement thus far, the underlying principles that all experimental designs must follow, and the early progress made towards utilizing synthetic molecular structures to perform tasks using mechanical motion. We also highlight some of the issues and challenges that still need to be overcome.

Synthetic molecular motors and mechanical machines.

The Feynman Lectures on Physics; Vol. I

The Feynman Lectures on Physics Addison-Wesley Reading

Introduction by Paul Davies Atoms In Motion Introduction Matter Is Made From Atoms Atomic Processes Chemical Reactions Basic Physics Introduction Physics Before Quantum Physics Nuclei and Particles The Relation Of Physics To Other Sciences Introduction Chemistry Biology Astronomy Geology Psychology How Did It Get That Way? Conservation Of Energy What Is Energy? Gravitational Potential Energy Kinetic Energy Other Forms of Energy The Theory Of Gravitation Planetary Motions Keplers Laws Development of Dynamics Newtons Law of Gravitation Universal Gravitation Cavendishs Experiment What Is Gravity? Gravity and Relativity Quantum Behavior Atomic Mechanics An Experiment with Bullets An Experiment with Waves An Experiment with Electrons The Interface of Electron Waves Watching the Electrons First Principles of Quantum Mechanics The Uncertainty Principle.

Matthew Sands

Papers

The Feynman Lectures on Physics; Vol. I

The Feynman Lectures on Physics Addison-Wesley Reading

Six Easy Pieces: Essentials of Physics Explained by Its Most Brilliant Teacher

Feynman Lectures on Physics, Volume 2: Mainly Electromagnetism and Matter

The Feynman Lectures on Physics, Vol. 3: Quantum Mechanics